Information management systems are being developed to track the location and/or status of a large variety of mobile entities such as products, vehicles, people, animals, etc. A widely used tracking technology uses so-called RFID tags that are placed physically on the items being tracked. Reference herein to “items” being tracked is intended to include the variety of entities just mentioned as well as, more commonly, product inventories.
RFID tags may be active or passive. Active tags typically have associated power systems and can transmit data over modest distances. Passive systems lack internal power but derive transmitting signal power from an incoming RF signal. However, transmitting distances with passive RFID tags are very limited. To read a large number of RFID tags, spread over a wide physical area, requires either a large number of RFID readers, or a reliable system of moving RFID readers. One proposed solution to this problem is to use active RFID tags on the products. However, active tags are relatively costly. Although they lend more function to a tracking system, and transmit more effectively, passive tags are typically more cost effective where inventories being tracked are large.
What is needed is an improved system for RFID tracking where the scale of the application exceeds the performance capability of conventional RFID approaches.